在奇异点处同步谱与干涉临界性

中文摘要 AI 辅助

奇异点（EPs）是谱奇异点，但它们能否用于控制一种不同的相干干涉临界性，在很大程度上仍未得到探索。在这里，我们展示了在非局域超导输运中，谱临界性和干涉临界性如何被可控地同步。在一个最小的超导双量子点系统中，损耗不平衡选择性地驱动一个玻戈留玻夫扇区通过奇异点。谱奇异点和CAR-ECT干涉临界性在控制空间中形成不同的结构，其相对排序可以连续调谐。在它们的同步点处，交叉安德烈耶夫反射（CAR）和弹性共隧穿（ECT）之间的干涉边界在奇异点处合并，并在其之外分叉，从而产生一个有限的CAR主导窗口。由此产生的干涉窗口以平方根临界律打开，该指数也支配着有限温度下的可观测性尺度。失谐展开两种临界性，而重新调谐恢复它们的交点，从而确立同步是受控的而非普遍的。分叉在非局域电导中直接可观测。我们的结果确立了奇异点作为独立定义的干涉临界性的谱控制点，开辟了一条非厄米控制临界量子干涉的途径。

英文摘要

Exceptional points (EPs) are spectral singularities, but whether they can be used to control a distinct criticality of coherent interference remains largely unexplored. Here we show in nonlocal superconducting transport how spectral and interference criticalities can be controllably synchronized. In a minimal superconducting double-quantum-dot system, loss imbalance selectively drives one Bogoliubov sector through an EP. The spectral EP and the CAR-ECT interference criticality form distinct structures in control space whose relative ordering can be continuously tuned. At their synchronization point, the interference boundaries between crossed Andreev reflection (CAR) and elastic cotunneling (ECT) coalesce at the EP and bifurcate beyond it, creating a finite CAR-dominated window. The resulting interference window opens with a square-root critical law, whose exponent also governs the finite-temperature observability scale. Detuning unfolds the two criticalities, while retuning restores their intersection, establishing the synchronization as controlled rather than generic. The bifurcation is directly observable in nonlocal conductance. Our results establish exceptional points as spectral control points for independently defined interference criticalities, opening a route to non-Hermitian control of critical quantum interference.

发表机构

• International Quantum Academy（国际量子研究院）
• University of Science and Technology of China（中国科学技术大学）

机构由 AI 辅助整理，请以论文原文为准。

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6+23 pages, 3+4 figures